<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="/js/jquery-3.4.1.min.js" type="text/javascript" charset="utf-8"></script>
    <script src="https://cdn.tiny.cloud/1/no-api-key/tinymce/5/tinymce.min.js" referrerpolicy="origin"></script>
</head>
<body>

<textarea id="mytextarea">Hello, World!</textarea>
<button id="btnSubmit">提交</button>

<script>
    tinymce.init({
        selector: '#mytextarea'
    });

    $("#btnSubmit").click(function () {
        var content = tinymce.activeEditor.getContent()
        console.log(content);
    });
</script>
</body>
</html>